As David Luiz geared up to play against former club Chelsea in next week's Champions League last 16 first-leg tie, the Paris St Germain player said the Premier League leaders had improved as a team since he left eight months ago.

The centre half, who was sold to PSG for a fee that media reports put at £50 million, believes close-season signing Cesc Fabregas has made the runaway Premier League leaders a more formidable unit.

"Chelsea are better this season," Luiz told the Evening Standard newspaper. "Above all they are better balanced following the arrival of Fabregas.

"He is perhaps the player they were missing. He balances the midfield, makes the team play well and knows how to hold on to the ball.

"With the arrival of Diego Costa, a warrior forward who always wants to score and challenge defenders, and the continuity provided by Jose Mourinho in the dugout, it's logical Chelsea are stronger this season."

Luiz, who was used more last season in midfield by Mourinho than in defence, was in the Chelsea side that won Europe's elite club competition in Munich in 2012.

The Stamford Bridge outfit certainly have more Champions League know-how than PSG and the Brazilian acknowledges his former club are favourites to reach the quarterfinals.

"Chelsea are an experienced team that has already won the Champions League," said Luiz. "They are used to this and they knocked out PSG last year but we mustn't think about that too much.

"We have to up our level and play to our strengths. We'll have to do what we do best, going forward, playing to win. I have faith in my team."

Chelsea have a blank weekend ahead of Tuesday's tie while third-placed PSG entertain Caen in Ligue 1 on Saturday.

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